Matlab Simulation Study and Comparison of Different Multiple Carrier PWM Schemes For Multi Level CHB Inverter

This paper presents a comparative analysis of modulation schemes implemented on multi-level inverters (MLIs). A five level three phase Cascaded H-bridge multilevel inverter (CHBMLI) is simulated to compare the performance of various modulation techniques. In this paper, phase disposition pulse width modulation, phase opposition disposition pulse width modulation, alternate phase opposition disposition pulse width modulation, phase shifted pulse width modulation, third harmonic injection pulse width modulation, switching frequency optimal pulse width modulation(SFOPWM) and rotated carrier technique have been simulated and their THD and fundamental line-to-line voltages have been compared. This paper also shows the output voltage and THD improvement in the AC output when the reference modulating signal is injected with the third harmonic.